1. Field
Example embodiments relate to multi-bit memory elements, memory devices including the same, and/or methods of manufacturing the same.
2. Description of the Related Art
Examples of non-volatile memory devices include a resistive random-access memory (RRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase-change random access memory (PRAM), or the like. Among them, the RRAM is a resistive memory device which stores data based on a resistance change of a material. In the RRAM, the resistance of a resistance-change material is changed from a high-resistance state to a low-resistance state (also referred to as “ON state”) when a voltage applied to the resistance-change material is greater than, or equal to, a set voltage. The resistance of the resistance-change material is switched back to the high-resistance state (also referred to as “OFF state”) when a voltage applied to the resistance-change material is greater than, or equal to, a reset voltage.
Generally, a resistive memory device includes a storage node and a switching device. The storage node has a resistance-change material layer. The switching device is electrically connected to the storage node, and controls access of a signal to the storage node.
The need for high density and high performance of various nonvolatile memory devices, such as the resistive memory devices described above, are continuously increasing.